Abstract

Use of fibre reinforced polymer is becoming increasingly popular in FRP bridges. FRP offers high strength-to-weight ratio, corrosion and chemical resistance, and fast deployability. A major issue in its wider applicability is lack of understanding of joints. This paper presents a review of mechanical connection methods for FRP bridges. Slip and fatigue resistance are critical to any bridge design. While conventional methods of fitted bolts, rivets and high strength friction bolts are not suitable for FRP joints due to viscoelastic nature of the material, injection bolts offer cheap, convenient and reliable method of joining for FRP bridges. Injection bolts have been used in the past to repair old steel bridges. Inspiration is taken from these old steel bridges to see its potential in FRP bridges. The behaviour of resin injected bolted joints is tested in three stages: quality control tests, static creep tests and fatigue tests. Research shows that FRP joints with resin injected bolts have a promise in terms of achieving slip and fatigue resistance. Joints with injection bolts can withstand as much as 60% of the failure load applied in 4 million cycles. This proves that resin injected bolted joints can achieve comparable slip and fatigue resistance as high strength friction bolted joints. However, majority of research data is limited to testing single or double lap shear joints. More experimental and numerical research is needed to extend the characterisation of these joints to all FRP bridge components.

Keywords: FRP bridges; Bolted joints; Sustainable materials; Slip and fatigue resistance